Locomotive superheater



1930. J. E. MUHLFELD ET AL LOCOMOTIVE SUPERHEATER s Sheets-Sheet 1 Filed April 20. 1927 Y e! m mam a $5 w Dec. 1930- J. E. MUHLFELD ET AL 1,784,378

LOCOMOTIVE SUPERHEATER Filed April 20. 1927 3 Sheets-Sheet 2 INVENTORS 1930. J. E. MUHLFELD ET AL 1,734,378

LOCOMOTIVE SUPERHEATER Filed April 20. 1927 3 Sheets-Sheet .5

TV. B

Patented Dec. 9, 1930 UNITED STATES PATENT OFFICE JOHN E. MUHLFELD, OF SCAR-SDALE, AND JOHN C. CHAPPLE, OF BRDOKLYN,

NEW YORK LOGOMOTIVE SUPERHEATER Application filed April 20,

This invention relates to locomotive superheaters, and has for its primary object and purpose to provide an improved arrangement of the superheater header and elements whereby a very high degree of superheat may be obtained with a minimum fuel consumption, less loss in steam pressure between boiler and valve chests, a lesser amount of superheater heating surface and with greater aclv cessibility to the superheater header and elements for inspection and cleaning.

Heretofore, with the conventional arrangement of the superheater in relation to'the locomotive boiler, the superheater header has been located at the front end of the boiler with the saturated and superheated steam conducting elements or tubes projecting rearwardly into the fire tubes of the boiler for thegreater portion of the length of the latter. It is usual to arrange the superheater header inthe smoke box, and when the boiler fire tubes and flues become obstructed by honey-comb, ashes and other foreign material,they must'be blown out from the fire 5 box end of the boiler. This requires that a specially constructed flue-blowing or cleaning device he installed in the fire box, or on the other hand, that the fire be dumped and the locomotive cooled in order that a man may enter the fire box for the purpose of blowing out and cleaning the fines. lVe propose to obviate this difiiculty by mounting and arranging the superheater header at the fire box end of the boiler. The front ends of the fire tubes and flues are thus left unobstructed so that they can be readily blown out from the front end of the boiler without cooling the locomotive by merely opening the smoke box door and inserting the flue blowing device, through the door opening for the cleaning process.

It is also another object of the invention to provide a mounting and arrangement of 1 the superheater at the firebox end of the boiler and adjacent the rear end thereof where the superheater header will be direct-' ly subjected to the high temperaturegases and. the generate'd'heat most economically .utilized both in the production of saturated 1927. Serial No. 185,100.

steam in the boiler and in the production of superheated steam. It is a further object of our present improvements'to provide a mounting and arrangement of the superheater and the superheater elements which will operate somewhat in the manner of a radiant heat type of superdrawings, and subsequently incorporated in the subioined claims.

In the drawings, whereln we have illus trated one application of our present invention to a type of boiler as used in connection with high powered steam locomotives, and

in which similar reference characters designate corresponding parts throughout the several views,-

Figure 1 is a fragmentary longitudinal section through the locomotive boiler and fire box showing our improved superheater installation I Fig. 2 is a transverse sectional view taken on the line 2-2 of Fig. 1, and

Fig. 3 is a fragmentary vertical sectional view similar to Fig. 1, more particularly illustrating the mounting and arrangement of the superheater header with relation to one form of fire box construction.

Referring in detail to the drawings, for purposes of illustration, we have shown the rear vertical water leg 5 of a fire tube boiler, spaced upper steam drums 6 and the spaced lower drums 7 arranged at opposite sides of the fire box generally indicated. at 8, said lower drums being connected with the upper drums at opposite sides of the fire box by means of the vertical banks of tubes 9. It will however, be understood that the particular type of "bOllGl illustrated in the drawingsis 'not essential and'that the present type of fire tube boiler and may also be eminvention'is of general application'to any ployed in connection with boiler furnaces utilizing coarse or pulverized coal or lignite,

gas,oil, or other solid, liquid, or-gaseons fuels. A, I a a As herein shown, the superheater header below the fire tubes or flues 11, The superheater header may be located in any other convenient place, for example, at thetop or sides of the fire box or it may be sub ivided 1 intos two orv more parts differently or simi= larly located from which the superheater elementsmay enter the fire flues of the boiler. This headeris formed vwith the usual saturated and superheated steam receiving chambers with which the ends of the super; heater elements 12 are j suitably connected. Thesesuperheater elements are, each in the form of a tube bent to provide a single elongated-. loop:l3 which extends into the rear endof one of, the fire tubes or flues '11 and to a point adjacent the forward end thereof These elements may, however, be of double loop type, spiralledor of any other form of fires flue superheater, element.

To one part of the superheater header 10-, the saturated steam supply pipe 14 from the boiler is connected while the superheated steam receiving pipe 15 is connected to another part of the header and is adapted for connection with the steam chests of the locomotive cylinders in any approvedmanner.

Separate headers may be used for each of the saturated and superheated steam connections. v V

In Fig. 3 of the drawings We have shown the superheater header 10 arranged between the fire box flue sheet and the vertically} positioned protection plate 16 and-preferably belowthe fire box grate. Upon the upper end of this protection plateth'e forward end of the arch wall is supported asin Fig 1 of the drawings. The superheater elements 12 extend upwardly from the header 10 closely contiguous to the metal plate 16. The plate 16 thus protects the header and the superheater elements as well as the joint connec tions therebetween from the direct influence of the fire in the fuel bed and also prevents short circuiting of the products of combustion through the superheaterelements to the fire tubes without first passing around the rear end of the combustion chamber bafiie wall. The saturated andsuperheated steam pipes l l and 15 maybe conconductirgl 4 t e super-heater header by the connected to 'ventio'nal joints indicated at17, which in the arrangement showna re easily accessible for the purpose ofihspeetion-and rep-air; Iuewh of the arrangementsillustrated fuel consumed than is possible with the conventional arrangement/of the superheater header in the smoke box or other relatively low temperature zone. This high temperature iab'sorbedheat will tend to addto the degree of superheat taken on b the saturated steam in its passage throng the superheater elements.- in? contradistinction tothe giving oif or loss ofapa rt of the superheat in the" conventional arrangement ofthe suin the drawings, on account of the heat 'ab- 7 V sorbing qualities of the metal protection 7 perheater in the fiowof the steam, through the superheater'elements and the header between the saturated and superheated steam pipe connections with thelatten Fromfthe"foregoingyiit will be apparent that as the superheater header is located in the hottestzone at'the firev box end "of the boiler, a very; high degree of superheatmay be obtained.. with"economy in fuel consumption. Alsoyowingrto thislocation of the superheater, we are enabled-to use the single loop elements 12 extending into thefire flees so as to reduced obstruction of the fluesto a minimum, as well; as the resistancetothe flow of the steam passing through said superheater elements. Atthesame time, the super heat accumulated by the steam and the pres sure at which thissuperheated steam enters the steam chests of the cylinders will be ape preciably greater than has heretofore been obtained, thus resulting in; a material in crease in power outputand thermal efficiency of the locomotive and with greater economy than has heretoforebeen possible.

By the locationof the superheater elements rearwardlyof the lirebox fiue sheet, these elements will act as ascreen protecting-the flue sheetfrom the collection of honey-comb and other-foreign matterwhich-tends to obstru ct the draft through the fire tubes 1 or flues. However, when it becomes necessary to clean'outthesefiues, this maybe readily done by inserting the fiuegblower through the smoke box door at theforward endof'the boiler and delivering the blower pressure into trieforwar'd'endsnf the tubes; Thus; it is no t'neeessary to install a special tube cleaning-device in thelocomotive fire box or on the other hand, dump the fuelbed and cool th'e fire-bexand" frequently remove arch bricksothataman may enter the same and blow 'or otherwiseclean out the tubes.

-1 nesma'gemne of the: superheater at the fien't end ofthe' beiler inside of the smoke box, r on-the mp thoraci where it must be properly insulated, accessibility is dimcult;

With our invention,- Ky

heater either Within the fire box or above or below the same at the rear end of the boiler, it becomes more accessible for inspection, cleaning and repairs. Also with the conven tional arrangement of locomotive superheaters where the superheater elements are connected with the header inside of the smoke box, in the event that leakage occurs at these joint connections, the escaping steam interferes with the vacuum in the smoke box and consequently with the draft through the fire tubes and the production of steam. In our present invention, these joints being located at the fire box or outside of the smoke box, should any leakage occur, it will not affect the draft through the fire tubes so that the draft will not be affected and fuel consumption will not be increased in order to maintain the necessary steam pressure.

In the existing arrangement of superheaters where the superheater elements project into the forward ends of the fire tubes, in order to secure a sufficient degree of superheat, it is necessary to provide superheater elements of the so-called double loop type and to make these double loop superheater elements almost as long as the fire tubes into which they project. This not only seriously obstructs passage of the gases through the fire tubes but also increases frictional resistance to the steam passing through the superheater elements and substantially reduces the boiler pressure before the superheated steam reaches the engine cylinders. As above noted, we provide preferably a single loop superheater element extending into the rear ends of the fire tubes. With the present arrangement of the double loop superheater element extending into the front end of the fire tube, it is apparent that such construction and arrangement is very inefficient, as the final passage of the steam through the superheater element to the header travels from a hot zone at the rear end of the fire flue to a relatively cold zone at the forward end thereof and the steam therefore, necessarily, in its final pass, gives off and does not take on superheat. Also, in order to secure economically a high degree of superheat, it is not possible to obtain the full benefit of the combustion temperature in the fire box and maintain a suificiently high evaporative capacity to produce saturated steam in the boiler without maintaining an uneconomically high temperature in the boiler smoke box. With our invention however, the final passage of the steam in the superheater element is from a relatively cold zone to a comparatively hot zone at the fire box end of the boiler. It therefore, becomes possible to secure a very high degree of superheat and with a simpler form of the superheater elements without maintaining an abnormally high temperature in the smoke box. The superheater headers and elements are usually made of iron or steel casting or plates or of cold or hot drawn seamless steel tubing, but we propose when advisable or necessary, to produce these headers and elements from high heat resisting alloys. Several such alloys have been developed in recent years. For instance, these alloys exploited under the trade names of ascoloy, duralloy, fabrite, thermalloy, hardite, Beckett metal, and Elesco metal are suitable. for such purpose.

By enabling a substantial reduction in the smoke box temperature to be maintained by means of our invention, a greater proportion of the heat generated may be utilized for the purpose of evaporation to produce saturated steam in the boiler. Also the use of dead plates, baffle plates, dampers and other draft retarding appurtenances heretofore necessary in the smoke box on account of the location of the superheater header and elements at that point may be eliminated, thus making it possible to appreciably enlarge the locomotive cylinder exhaust nozzle and thereby reduce the cylinder back pres sure and the loss of power in the engine while producing the necessary draft for combustion. This also of course, renders the boiler fines and tubes more accessible for the purpose of cleaning and obviates the necessity of dumping the fuel bed and removing arch brick and other parts from the fire box as is the present practice in order to blow out the tubes from the fire box end of the boiler.

Heretofore, it has been a very time consuming and expensive matter to make necessary repairs to the superheater or any part of the boiler connected therewith, owing to the necessity of first removing the various appliances or accessories from the smoke box. Vith our invention, it is a'simple and easy matter to disconnect the superheater elements from the header and remove them from the fire tubes through the fire box without entering the smoke box or in any way disturbing the appliances there-in.

Preferably, in practice, we will arrange all of the superheater elements substantially as shown in the drawings at the rear end of the locomotive boiler adjacent the fire box flue sheet and connect them with a single header. However, if desired, a superheater'header may be arranged at the front end of the boiler and a number of superheater element-s connected therewith and extended into the upper fire fiues while the remaining superheater elements are connected with a separate header at the fire box flue sheet and extended into the lower fire fines. Of course with this arrangement, suitable means will be provided for connecting the saturated and superheated steam pipes leading respectively to and from the different superheater headers to the locomotive boiler and the engine cylinders respectively.

From the foregoingdescription considered in connection with the accompanying drawings, itis believed that the'construction and relative arrangement of the several 1 parts of our invention as well as'the numerous advantages to be derived therefrom willbe clearly and fully understood. Of

' course, it is apparent that in so far as the fundamental feature of our present dis- "closure residing in the new location or arrangement of the superheater with respect to they locomotive boiler is concerned, other forms] of the superheaterelements as well as other forms or constructions of the superheater header might be employed. Also, it

t will be apparent that if desired, the superheater header might be mounted and arranged above the fire tubes or flues so that the superheater elements'will extend downwardly therefrom and into the respective tubes, instead ofthe reverse arrangement as shown in the drawings. Accordingly, it is tobe understood that in the application of our invention to various different types of fire tube boilers, numerous alternatives in the form and constructlon of the several parts as well as the specific location and mounting thereof relative'to the fire tubes as herein illustrated might be resorted to, and we there fore, reserve the privilege of adopting all such legitimate changes therein as may be fairly incorporated within the spirit and scope of the invention as claimed.

' We claim:

, 1. In combination with a locomotive fire tube boiler and fire box and a vertically posi- 'tioned protection wall at the front end of the fire box in spaced relation to the fire tube fiue' sheet, a superheater header mounted between said protection wall and the flue sheet below the open ends of the fire tubes, and superheater elements connected withflsaid header; and having parts p'osi tioned contiguous to said protection wall and extending forwardly into the fire tubes.

adjacent to the boiler flue sheet and below the path of flow of the products of combustion. V 3. In combination with a locomotive the tube boiler and a firebox having an end wall spaced from theadjacent boiler flue sheet, a

superheater header mounted in the space between said firebox wall and flue sheet and below the: zone of fuel combustion, and superheater elements connected to said superheaterheader extending upwardly through said space and'forwardly into the boiler fire tubes. v r

In testimony that we claim the foregoing as our invention, we have signed our names hereto. i i

- JOHN E. MUHLFELD. I 'JOHNGGHAPPLE. I

In combination with a fire tube boiler and a. fire -box,a superheater header mounted 

